688 research outputs found

    A Novel QoS provisioning Scheme for OBS networks

    Get PDF
    This paper presents Classified Cloning, a novel QoS provisioning mechanism for OBS networks carrying real-time applications (such as video on demand, Voice over IP, online gaming and Grid computing). It provides such applications with a minimum loss rate while minimizing end-to-end delay and jitter. ns-2 has been used as the simulation tool, with new OBS modules having been developed for performance evaluation purposes. Ingress node performance has been investigated, as well as the overall performance of the suggested scheme. The results obtained showed that new scheme has superior performance to classical cloning. In particular, QoS provisioning offers a guaranteed burst loss rate, delay and expected value of jitter, unlike existing proposals for QoS implementation in OBS which use the burst offset time to provide such differentiation. Indeed, classical schemes increase both end-to-end delay and jitter. It is shown that the burst loss rate is reduced by 50% reduced over classical cloning

    Sport Management Student as Producer: Embedding Critical Management Studies in Sport through Contemporary Pedagogy

    Get PDF
    In recent years there has been growing interest over the role of major sport events and the sports industry. The aftermath of 2008 global crisis exposed the myth of ‘end of history’ and raised several questions over the role of management and organisational practices and theories in all aspects of human activity, including sport. This article reviews the emergence of critical management studies (CMS) as a field within management and organisational studies. We focus on critical performativity theory (CPT) as a key concept of re-configuring managerial practices. We add our voices to those asking for more critical output in sport management and point out the potential contribution of CMS in sport and especially of CPT. Finally, we propose ‘student as producer’ as a pedagogical framework to act as a possible basis for incorporating critical theories into higher education teaching. We argue that this framework can contribute significantly towards providing future graduates with the skills and knowledge to enable them to deal with the contemporary challenges of modern sport’s industry and wider society

    A novel ingress node design for video streaming over optical burst switching networks

    Get PDF
    This paper introduces a novel ingress node design which takes advantage of video data partitioning in order to deliver enhanced video streaming quality when using H.264/AVC codec over optical burst switching networks. Ns2 simulations show that the proposed scheme delivers improved video traffic quality without affecting other traffic, such as best effort traffic. Although the extra network load is comparatively small, the average gain in video PSNR was 5 dB over existing burst cloning schemes, with a maximum end-to-end delay of 17 ms, and jitter of less than 0.35 ms

    Phase-encoded duobinary transmission over non-dispersion shifted fibre links employing chirped grating dispersion compensators

    No full text
    High-bit-rate (10Gbit/s, 1.55µm) phase-encoded duobinary transmission over non-dispersion shifted fibre links employing chirped grating dispersion compensators is analysed. A reduced sensitivity to optical nonlinearities allows increased transmission powers and thus distance, 1700km compared to 1000km for the conventional NRZ-format. In addition for typical links around 700km an increased dispersion margin is observed, equivalent to ±60km compared with ±25km for the NRZ format

    Comparative field studies of various traps and attractants for the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) in fall

    Get PDF
    Για την επιλογή της πλέον αποτελεσματικής παγίδας και ελκυστικού μεταξύ ορισμένων από τους τύπους παγίδων και ελκυστικών ουσιών που χρησιμοποιούνται σήμερα για την παρακολούθηση και καταπολέμηση της μύγας της Μεσογείου, Ceratitis capitata, (Wiedemann) (Diptera: Tephritidae), συγκρίθηκαν σε πορτοκαλεώνες επτά τύποι παγίδων (δύο τύπου MePhail, Υαλοπλαστική, χάρτινο-δίπτυχο, χάρτινος φάκελος-χαρτοπλαστική, διαφανής πλαστική φιάλη, παγίδα ξηρού τύπου), τέσσερα τροφικά ελκυστικά ( Dacus bait 100, Entomela 12SL, όξινο ανθρακικό αμμώνιο και το με κωδικό ZI), ένα ελκυστικό φύλου (Trimedlure) και ένας συνδυασμός τροφικού και ελκυστικού φύλου (Όξινο ανθρακικό αμμώνιο+Trimedlure). Τα αποτελέσματα έδειξαν ότι μεταξύ των παγίδων τύπου MePhail δεν υπάρχουν σημαντικές διαφορές.Η παγίδα τύπου πλαστικής φιάλης απεδείχθη πολύ αποτελεσματική όταν πληρούται με το ZI (πρωτεϊνικό τροφικό ελκυστικό). Από τα δοκιμασθέντα ελκυστικά , τα πλέον αποτελεσματικά ήταν το ZI και το Entomela. Ο συνδυασμός ελκυστικών τροφής και φύλου δεν έδειξε σημαντική συνεργιστική δράση στην αποτελεσματικότητα της παγίδας. Τα αποτελέσματα επιτρέπουν μια καλύτερη επιλογή μεταξύ των παραπάνω τύπων παγίδων και ελκυστικών, για παρακολούθηση και καταπολέμηση της μύγας της Μεσογείου.To clarify questions regarding the effectiveness of the many different types of traps and semiochemicals used for the monitoring and the control of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Diptera: Τephrititae), seven trap types, four food attractants, one sex attractant and a combination of food and sex attractant, were evaluated under field conditions in orange orchards in fall. No major differences were observed between trap designs resembling the original McPhail glass trap. The plastic bottle trap of 1,5L volume, with four side openings for one-way fly entrance, proved very efficient when filled with a proteinaceous food attractant Ζ1. From the attractants, two of them, Ζ1 and Entomela showed the best performance. The combination of food and a sex attractant showed no significant synergistic effects on trap efficiency. The findings allow a better choice among trap types and attractants, available today in the market, for Medfly monitoring and control

    Online simulation games for guided learning: a sport business case study

    Get PDF
    Business simulation games (BSG) have become a very popular pedagogical tool in university courses and programmes all around the world. Their immense popularity has been a subject of research and academic discourse, especially the past twenty years when many experts have called for more student-centric and reality based pedagogical approaches. Their implementation in business schools has been particularly successful, leading to improved student outcomes, satisfaction and skills development. Their use in sport business courses, though, has been surprisingly neglected in the pertinent literature. In the present study, we attempt to close this gap in the literature by exploring the effectiveness of BSG implementation in sport business courses, as well as the conditions and factors that facilitate the teaching and learning experience in such cases. In doing so, this research followed a mixed methods case study approach. Our findings expand previous conclusions and arguments on the effectiveness of BSGs’ use in universities, to the case of sport business courses. They also identify conditions under which the teaching and learning experience is improved, namely effective group work, student engagement, satisfaction from the game and others. Based on these findings we propose useful recommendations and suggestions for future research. We also establish BSG as a form of independent, guided learning activity which is facilitated merely by individual engagement and group work and less from the tutors

    Gridless optical networking field trial: flexible spectrum switching, defragmentation and transport of 10G/40G/100G/555G over 620-km field fiber

    No full text
    We report the first gridless networking field trial with flexible spectrum switching nodes over 620 km field fibre links. Successful transport, spectrum switching and defragmentation achieved for mixed line signals including 555G and coherent 100G

    Acute Respiratory Distress due to Thymoma in a Patient Treated with TK Inhibitor: A Case Report and Review of the Current Treatment Options

    Get PDF
    Thymic malignancies are rare intrathoracic tumors that may be aggressive and difficult to treat in advanced stage. Surgery is the cornerstone of the management of thymomas: it is significant for the definite histopathological diagnosis and staging, and in most cases, it constitutes the first step of the treatment strategy. For patients with primary unresectable thymomas, the multimodal treatment schedule nowadays includes neoadjuvant chemotherapy, extensive surgery, adjuvant radiotherapy, and in some cases, adjuvant chemotherapy. A patient with a history of stage III COPD and an undiagnosed thoracic mass was admitted to the intensive care unit with acute respiratory distress. A radiologic evaluation by CT scan revealed a mass of 13 cm in diameter at the mediastinum. Fine needle aspiration was performed and revealed a thymoma. Due to poor performance status, the patient was not able to undergo surgery. He refused to be treated with neither chemotherapy nor radiotherapy, but due to EGFR overexpression, treatment with TK inhibitor was suggested. Fine needle aspiration biopsy is commonly used to identify metastasis to the mediastinum. However, it is less often employed as a primary diagnostic tool for tumors, particularly thymic neoplasms. The use of targeted therapies for the treatment of thymic malignancies has been described in the literature. Over the past years, significant efforts have been made to dissect the molecular pathways involved in the carcinogenesis of these tumors. Insights have been obtained following anecdotal clinical responses to targeted therapies, and large-scale genomic analyses have been conducted
    corecore